Grease and flour a round tin and set aside to start with and also preheat the oven to 175 degrees.
Melt the butter and chocolate in a pan, and set aside to cool down. Also, mix the espresso with hot water and also set aside to cool down.
For 5 of the eggs, separate the whites from the yolks. Break 2 full eggs and mix them with only with the yolk of the previous 5 eggs, along with salt, cocoa powder, espresso and sugar. Hand whisk them to combine the ingredients well.
Add the cooled melted chocolate and butter mixture to the whisked bowl and mix again until well combined.
Whisk the separated egg whites until fluffy like clouds to a point where if you turned the bowl upside down, it would not fall out of the bowl.
Add the whisked egg whites to the main bowl and mix together until combined. Once combined well, stop mixing – we do not want to over mix them. The mixture will be fluffy like clouds.
Pour the mixture into the tin you set aside right at the beginning, and bake for 25 – 30 minutes or until the centre is no longer wobbly.
Bring the cake out and set aside on cooling rack to completely cool – do not touch the cake for a minimum of 2 hours.
Sprinkle more cocoa powder to finish off.
Serve and enjoy